A 28-year-old woman from Delhi presents on day 5 of fever with severe retro-orbital pain, myalgia, and a blanching maculopapular rash over her trunk and limbs. Her platelet count is 85,000/μL, haemoglobin 14.2 g/dL, and haematocrit 38%. Liver enzymes are mildly elevated (AST 120 U/L, ALT 95 U/L). She denies abdominal pain, bleeding manifestations, or respiratory distress. Blood pressure is 110/70 mmHg. What is the most appropriate clinical classification and immediate management?